The invention relates to a novel tongue and groove profile for use in joining wood-based boards or panels comprised of plywood, oriented strand board (OSB), waferboard, particleboard, fiberboard or other similar wood based materials.
The use of tongue and groove profiles for joining panels or boards for construction of floors, roofs and other building structural features is well known. Tongue and groove profiles allow two boards or panels to be interlockingly joined during construction. In construction of a building structure, the panels span the distance between supporting joists with the interlocking tongue and groove side edges of adjacent panels serving to support the panels against deflection between the joists while the end edges of the panels are located over and supported by the joists.
Prior tongue and groove profiles in use have experienced several problems, however. A prior tongue and groove profile design (see FIG. 1) was constructed such that the inner walls of the groove were essentially parallel with the exception of the innermost region of the groove adjacent to the base of the groove where the groove is narrowed to accommodate the tongue tip. The opening or clearance of the groove is only slightly larger than the thickness of the tip of the tongue. This results in some difficulty of insertion of the tongue into the groove during the installation process. Installation can be especially difficult if panels are bowed, or the edges of the panels are deformed or swollen due to an increased water content in the panels. To avoid such problems, a tongue and groove structure comprised of a tongue that is slightly longer in length than the length of the groove and in which a notch is cut through the tongue has been used. The notches are intended to enable water to drain out. To ensure that the notches are not closed off by edge-to-edge contact of mated panels, the tongue is made longer than the groove. Without the notches, water could accumulate on top of the panels thereby increasing the risk of swelling or buckling of the panels, which are undesirable conditions. Edge sealers can be applied to the edges of panels to inhibit the swelling of panels caused by moisture. However, prior tongue and groove designs were difficult to adequately seal in this manner due to the narrow opening of the mouth of the groove and the direction of the sealant being essentially parallel to the machined surfaces of the tongue and groove.
Another disadvantage of prior tongue and groove profiles was that markings were necessary on the panels because the panels had to be oriented with a particular surface facing up or down to enable a satisfactory interlocking joint with the adjacent panel.
Additionally, when adhesive was desired for a secure fit of two joined panels, prior tongue and groove profiles were prone to overfilling with adhesive because there was not a properly designed gap between the tongue and groove when interfit and excess adhesive could squeeze out onto the surfaces of the panels creating a messy, undesirable condition.
Accordingly, there is a need for a tongue and groove profile which is of a configuration enabling a close interlocking mating relationship between two construction panels and which enables a large load transfer capacity and which can be used in multiple applications in construction, but yet is not subject to severe deformation if the panels are exposed to moisture.